Is Running Bad for Your Knees?

“Running ruins your knees” is one of the most durable fitness warnings, and one of the most common reasons people avoid starting. The research tells a more reassuring story for everyday runners, with a caveat for the very high end. This is general education, not medical advice.

Where the fear comes from

Running is repetitive, and each stride loads the joints. It seems logical that thousands of impacts would wear the cartilage down over the years. Reports of knee and hip arthritis in elite runners fed the idea, and it stuck.

What a large review found

In 2017, researchers led by Eduard Alentorn-Geli published a systematic review and meta-analysis in the Journal of Orthopaedic and Sports Physical Therapy. It covered 25 studies and about 125,000 people, and looked at hip and knee osteoarthritis in recreational runners, competitive runners and people who did not run.

• Recreational runners: about 3.5 percent had arthritis.
• Non-runners (comparison group): about 10.2 percent.
• Competitive runners: about 13.3 percent.

In other words, recreational running was not linked to more arthritis, and if anything it was linked to less. The higher rate in competitive runners was suggestive, but its statistical range was wide enough that a true difference was not clearly established.

Why this might be

• Joints respond to moderate load. Cartilage tends to adapt to regular, moderate loading, and running can help maintain it.
• Running lowers weight and inflammation for many people, both of which put less strain on knees.
• Elite runners differ. They run far more, often with earlier injuries, and the study could not tell whether volume itself caused the extra arthritis.

Limits to keep in mind

• Most of the data are observational. People who keep running may be those whose joints cope well, which can flatter the results.
• Existing knee problems are a different question. The findings apply to people without a pre-existing condition. If you have knee pain, a past injury or arthritis, a clinician or physical therapist can advise.
• Combined hip and knee figures. The percentages cover both joints, not the knee alone.

Looking after your knees as a runner

• Build up gradually. Increase distance and speed slowly to give tissues time to adapt.
• Mix in strength work. Strong legs and hips help share the load. See strength training for beginners.
• Choose comfortable shoes and softer surfaces when you can.
• Take a day off between runs when starting. Walking is a good middle step, as in how much walking is enough.
• Listen to pain. A sharp or persistent pain is a reason to stop and get it checked.

A fair summary

For most recreational runners, the evidence does not support the fear that running wrecks the knees. If you enjoy it and your joints feel good, it is not something the research says you need to avoid. And if running is not for you, plenty of other movement counts, as our guide to how much exercise helps with weight loss explains.

Sources

• Alentorn-Geli E, Samuelsson K, Musahl V, Green CL, Bhandari M, Karlsson J. The association of recreational and competitive running with hip and knee osteoarthritis: a systematic review and meta-analysis. Journal of Orthopaedic and Sports Physical Therapy, 2017;47(6):373-390.